Swash plate compressor

ABSTRACT

An improved swash plate compressor provided with a pair of cylinder blocks comprising an aluminum block portion cast with a filler provided with a plurality of sleeves connected to each other with a connecting member. Each sleeve forms a cylindrical bore for receiving a piston which is reciprocally moved in accordance with the motion of the swash plate. The connecting member may be provided with a side surface which bears the thrust force created by the swash plate. The filler is made of a metallic material having a property of high abrasion resistance, such as sintered metal.

United States Patent 1191 Nakayama et al.

Kabushiki Kaisha Toyoda Jidoshokki Seisakusho, Aichi-ken, Japan Filed: Nov. 20, 1973 Appl. No.: 417,533

Related US. Application Data Continuation of Ser. No. 118,252, Feb. 24, 1971, abandoned.

Assignee:

U.S. C1. 29/156.4 WL. 29/445, 29/527.5 Int. Cl. 823p 15/00, F04b 1/14 Field of Search 417/269; 164/333; 29/156.4 WL, 445, 527.5

References Cited UNITED STATES PATENTS Feb. 11, 1975 3,352,485 11/1967 Akira Niki et al 417/269 FOREIGN PATENTS OR APPLlCATlONS 564,921 10/1923 France 417/2119 Primary Examiner-William L. Freeh Attorney, Agent, or Firm-Robert E. Burns; Emmanuel J. Lobato; Bruce L. Adams [57] ABSTRACT An improved swash plate compressor provided with a pair of cylinder blocks comprising an aluminum block portion cast with a filler provided with a plurality of sleeves connected. to each other with a connecting member. Each sleeve forms a cylindrical bore for receiving a piston which is reciprocally moved in accordance with the motion of the swash plate. The connecting member may be provided with a side surface which bears the thrust force created by the swash plate. The filler is made of a metallic material having a property of high abrasion resistance, such as sintered metal.

2 Claims, 10 Drawing Figures MENFEB FEBI 1 I975 3.864801 SHEET SM 6 FATE-min mm ms SHEET 8 OF 6 //l I ll/ SWASH PLATE COMPRESSOR This is a continuation, of application Ser. No. 118,252, filed Feb. 24, 1971 now abandoned.

BRIEF SUMMARY OF THE INVENTION This invention relates to a gas compressor and more particularly to an improvement of a swash plate compressor for use in refrigerating systems and the like.

Generally, it is required to construct the compressor compact for use as an air conditioning apparatus of an automobile, and aluminum alloy casting is mainly applied to make the cylinder blocks of the compressor. However, as the aluminum alloy casting is deficient in abrasion durability, some means for reinforcing the durability, such as an additional insertion of a sleeve into a bore of each cylinder or plating the bore of each cylinder with chrome, are utilized.

However, in the case of insertion of sleeves into the cylindrical bores, since making a tapered bore is inevitable, in order to take a mold after completion of the casting operation, each casting cylindrical bore must be worked to finish the size and shape thereof for receiving a sleeve by applying the cutting or grinding operation of the bore, while each sleeve must be subjected to the grinding operation to finish the peripheral surface and the inside cylindrical surface thereof. Consequently, the machine works, to produce the cylindrical blocks applied to the refrigerating apparatus, become very complex and further, production cost is increased. On the other hand, in the case of applying the chrome plating, the production cost is also increased.

The principal object of the present invention is to provide an improved refrigerating apparatus provided with a pair of cylindrical blocks each being cast with a filler provided with a plurality of cylindrical bores for receiving respective pistons.

However, even though the above-mentioned improvement is applied, the following drawback still remains in the refrigerating apparatus. That is, as it is difficult to plate a thrust surface of the cylinder block contacting a bearing which bears the thrust force acting upon a swash plate of the refrigerating apparatus, the contacting surface made of an aluminum alloy is usually subjected to contact the thrust bearing directly. However, as each end surface of the thrust bearing is supported between an end surface of a boss of the swash plate and the above-mentioned contacting surface, it is inevitable to prevent the low speed rotation of a side plate of the thrust bearing due to the high speed rotation of the swash plate, so that the contacting surface is subjected to wear.

Therefore, it is a further object of the present invention to additionally improve the swash plate compressor provided with a plurality of cylinder blocks, each being cast with a filler provided with a plurality of cylindrical bores for receiving respective pistons, by applying a reinforced bearing member which contacts the thrust bearing, wherein these sleeves and reinforced bearing member are formed as one body.

To attain the above-mentioned object, in addition to the first mentioned improvement characterized by the above-mentioned filler, a bearing member, contacting the thrust bearing is formed as one body with the sleeves by using a metallic material having high abrasion resistance.

It is a still further object of the present invention to provide the swash plate compressor comprising a pair of cylinder blocks, each being cast with a filler provided with a plurality of cylindrical bores for receiving the respective pistons and a bearing member comprising a surface contacting the thrust bearing and, a radial bearing portion directly supporting a drive shaft, or a cylindrical recess for receiving a needle bearing which supports the drive shaft, by using a metallic material having high abrasion resistance.

Further objects and advantages of the present invention will be apparent from the following description. reference being made to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a vertical-sectional view of the compressor showing an embodiment of the present invention,

FIG. 2 is a perspective view showing a filler provided with three sleeves connected as one body, which is cast with each cylinder block of the compressor shown in FIG. 1,

FIG. 3 is a perspective view showing another embodiment of a filler according to the present invention, wherein three sleeves are connected to each other by applying a different way of connection from the embodiment shown in FIG. 2,

FIG. 4 is a vertical-sectional view of the compressor, showing a further improvement of the apparatus, according to the present invention,

FIG. 5 is a perspective view of a cylinder block of the apparatus shown in FIG. 4,

FIG. 6 is a vertical-sectional view of the compressor, showing a modification of the apparatus shown in FIG.

FIG. 7 is a perspective view ofa cylinder block of the apparatus shown in FIG. 6,

FIG. 8 is a sectional view of the cylinder block of the apparatus shown in FIG. 6,

FIG. 9 is a vertical-sectional view of the further modification of the apparatus shown in FIG. 6,

FIG. 10 is a sectional view of a cylinder block of the apparatus shown in FIG. 9.

DETAILED DESCRIPTION The present invention is hereinafter illustrated in detail in connection with several embodiments.

Firstly, an improvement of the refrigerating apparatus including an improvement to attain the first object is illustrated, reference being made to FIGS. 1 and 2. In a swash plate compressor shown in these drawings. a drive shaft 2 is connected to a driving mechanism of an engine of the vehicle through connecting means (not shown), the shaft 2 passes through a bearing portion 19 of a cylinder block 6 which is cast with a filler 5 and a cylindrical connecting member 7 of a filler 5. The filler 5 is provided with three sleeves connected with the connecting member 7, each sleeve 8 forms a cylindrical bore 10 for receiving a piston 3. The shaft 2 is also rotatably supported by a pair of needle bearings 25 and a swash plate 1 is secured upon the shaft 2 at a position corresponding to a space between two cylinder blocks 6. Three sleeves 8 are arranged in parallel in such a way that their central axes are spaced from the shaft 2 in a regular triangular relationship. These two cylinder blocks 6 are arranged in such a way that the respective cylinder bores 10 of the sleeves 8 face each other so that three pistons 3 reciprocate in response to rotation of the shaft 2. Each of the pistons 3 is provided with a pair of sliding parts at both ends thereof, and a central part of its one side cut away, so as to straddle the outer edge of the swash plate 1. This central part engages with both sides of the swash plate 1 through ball bearings 11 which are disposed between ball sockets 3a formed in the piston 3 and thrust bearing shoes 12 which are arranged to slide on the swash plate 1 as shown in FIG. 1.

Functions of other elements of the compressor are similar to the conventional apparatus such as the refrigerating apparatus shown in US. Pat. No. 3,352,485, for example, the gas to be compressed is admitted into suction chambers 14 formed in the front and rear cylinder heads 24, 28 through an inlet line 16. A pair of valves (not shown) are arranged in abutting relationship to the cylinder heads 24, 28 and are provided with a pair of passages (not shown) which communicate with cutaway portions in the cylinder blocks 6.

Further, reference numeral 18 designates an outlet line through which the compressed gas is discharged from a discharged chamber 13, reference numeral 21 designates a stamped sheet metal outer housing element supporting the cylinder head 24 and 28. The outer housing element 21 is provided with a bulge portion which forms an oil pump. Reference numeral 17 designates an oil pick-up tube which communicates with aligned passages 29 in the various compressor components. 1

A separate valve plate 22 and intake reed 23 is provided adjacent each end of the cylinder blocks 6. A stop for restricting the inward motion of the intake reed 23 is formed at an outside edge of each sleeve 8. (The above-mentioned stop is particularly designated as reference 32 in FIG. 6.)

In the above-mentioned embodiment, means for connecting three sleeves 8 as one body is not limited to the form of the cylindrical connecting members 7, that is, any separate connecting members symmetrically disposed between these sleeves 8 may be applied to attain the object of the present invention as shown in FIG. 3, even though these connecting members do not form a cylindrical member which permits the shaft 2 to pass therethrough. In any case, the above-mentioned sleeves 8 and the connecting member 7 must be made ofa metallic material having high abrasion resistance, while the cylinder block 6 is made of aluminum alloy.

The above-mentioned cylinder block 6 is made by applying casting, that is, after preparation of sleeves 8 connected by the connecting member 7 as a filler 5, this filler 5 is inserted into a mold to use for casting the cylinder block 6, and then the casting operation for producing the cylinder block'6 is carried out. Therefore, precise arrangement of the sleeves 8 in the cylinder block 6 can be attained very easily with less additional machine works so that the manufacturing cost can be remarkably reduced.

Further, it is noticed that, as three sleeves 8 are connected to each other so that any turning thereof can be completely prevented, the possible interference between the swash plate 1 and the inside edge of the sleeves 8 is eliminated, while the relative position of the intake reed 23 to the stop 32 can be permanently maintained in a correct condition.

Further improvements are shown in the following embodiments, wherein a bearing member contacting the thrust bearing 4 is formed as a portion of the connecting member. In these embodiments, components having the similar function as the above-mentioned embodiment are represented by the same reference numerals to avoid complexity of illustration.

The components of the swash plate compressor shown in FIG. 4 is almost similar to the first abovementioned embodiment except for the construction of the cylindrical connecting member 7.

In this embodiment, the drive shaft 2 passes through the bearing portion 19 of the cylinder block 6, the cylindrical connecting member 7 and a central portion of the front cylinder head 24 and is rotatably supported by the pair of needle bearings 25 at their both end portions. The swash plate 1 is secure upon the shaft 2 at a position corresponding to the space between two cylinder blocks 6. In accordance with the reciprocal motion of the pistons 3 within cylindrical bores 10 of the sleeves 8, a thrust force is imparted to the boss of the swash plate 1 so that the thrust bearings 4 bear this thrust force. As a side surface 7a of the connecting member 7 directly contacts the thrust bearing 4 and the side surface 7a has a high abrasion durability, because of the metallic material of the connecting member. 7. This is the second object of the present invention which can be attained.

In the abobve-mentioned invention, the cylinder blocks 6 may be produced as one body with the outer housing element 21 by casting. Further, the equivalent effect to the above-mentioned embodiment can be obtained by connecting the cylindrical connecting member 7 with one of the sleeves 8.

In the embodiment shown in FIG. 6, the construction of the compressor is similar to the second embodiment shown in FIG. 4, except for means for supporting the drive shaft 2 and construction of the cylinder blocks including three sleeves together with the cylindrical connecting member.

The construction of the cylinder blocks 6 is clearly shown in FIGS. 7 and 8. That is, each cylinder block 6 is cast with a tiller 5 comprising three sleeves 8 connected by a cylindrical connecting member 26. The connecting member 26 comprises an annually projected portion 20 which contacts the thrust bearing 4 and a radial bearing surface 30. In each cylinder block 6, the sleeves 8 are arranged in parallel in such a way that their central axes are spaced from the shaft 2 in a regular triangular relationship.

A metallic material having sufficiently high abrasion resistance is used for the connecting member 26 and the wearing of the annularly projected portion 20 bearing the thrust force can be remarkably reduced.

Further, the shaft 2 is rotatably supported at its main portion by the cylindrical connecting member 26, so that bending of the shaft 2 is completely prevented. Consequently, the possibility of bias loading upon the shaft 2 and the connecting member 26 is prevented so that the durability of the component elements of the apparatus is enhanced.

It is also a characteristic feature of the abovementioned apparatus, that any radial needle bearing which may be inserted between the shaft 2 and the connecting member 26 is omitted. The deformation of the shaft 2 which is always created by the above-mentioned insertion can be avoided so that the slidable engagement of the piston 3 with the cylindrical bore 10 of the sleeve 8 is maintained in satisfactory condition to carry out a smooth operation. As the radial needle bearing can be omitted, and the radial bearing portion 30 and the annular projected portion 20 are arranged as one body with the cylinder block 6, the production cost of the apparatus can be remarkably reduced.

The embodiment shown in FIG. 9 has almost the same construction as the apparatus shown in FIG. 4, except for the connecting member 31. In the drawing, the connecting member 31 comprises the annularly projected portion 30 which bears the thrust force caused by the thrust bearing 4 and cylindrical recess 27 for receiving a needle bearing 25. As shown in FIG. 10, in this embodiment, each cylindrical recess for receiving the needle bearing 25 and the annually projected portion 20 are formed as portions of the cylindrical connecting member 31 and this connecting member 31 is connected with at least one sleeve 8 as one body. The above-mentioned body is disposed as a filler 5 in the mold for producing the cylinder block 6 at the time of casting thereof. As the metallic material ofthe cylindrical connecting member 31 is so selected as to have the same coefficient of linear expansion by heat as the needle bearing 25, the clearance for insertion of the needle bearing 25 between the shaft 2 and the cylindrical recess 27 can be reduced to as little as possible in the condition of avoiding the creation of strain upon the cylinder bore l0 of the sleeves 8 at the time of the above-mentioned insertion. Consequently, the circular cross-sectional shape of the bore 10 can be completely maintained so that the compression of the gas by the piston 3 can be satisfactorily attained.

Further, even though the temperature of the machine components is elevated during the compression opera tion, the fitting between the radial bearing portion formed in the cylindrical connecting member 31 with the needle bearing 25 is always maintained in good '6 condition so that the rotation of the outer ring of the needle bearing 25 together with the shaft 2 is completely prevented.

What we claim is:

1. A method of manufacturing a compressor cylinder block comprising providing an integral unit having a plurality of integrally joined sleeves defining corresponding cylinder bores assembled in fixed relationship, said integral unit comprising a bore defining a drive shaft bearing joining said sleeves integrally and holding said sleeves in fixed assembly accurately relative to each other and said bore, machining internal surfaces defining said bores, casting a cylinder'block having cast portions bonded to said integral unit fixing said integral unit in said casting and fixing said sleeves for access to said bores thereof from exteriorly of said casting.

2. A method of manufacturing a compressor comprising, a pair ofjuxtapostioned, spaced cylinder blocks having a plurality of cylindrical bores, comprising providing an integral unit having a plurality of integrally joined sleeves defining cylindrical bores assembled in fixed relationship, said integral unit comprising a bore defining a drive shaft bearing joining said sleeves integrally and holding said sleeves in fixed assembly rela-' tive to said bore, machining internal surfaces of said sleeves defining said bores, casting said cylinder as a casting having cast portions bonded to said integral unit fixing said integral unit in said casting and fixing said sleeves for access to said bores thereof from exteriorly 

1. A method of manufacturing a compressor cylinder block comprising providing an integral unit having a plurality of integrally joined sleeves defining corresponding cylinder bores assembled in fixed relationship, said integral unit comprising a bore defining a drive shaft bearing joining said sleeves integrally and holding said sleeves in fixed assembly accurately relative to each other and said bore, machining internal surfaces defining said bores, casting a cylinder block having cast portions bonded to said integral unit fixing said integral unit in said casting and fixing said sleeves for access to said bores thereof from exteriorly of said casting.
 2. A method of manufacturing a compressor comprising, a pair of juxtapostioned, spaced cylinder blocks having a plurality of cylindrical bores, comprising providing an integral unit having a plurality of integrally joined sleeves defining cylindrical bores assembled in fixed relationship, said integral unit comprising a bore defining a drive shaft bearing joining said sleeves integrally and holding said sleeves in fixed assembly relative to said bore, machining internal surfaces of said sleeves defining said bores, casting said cylinder as a casting having cast portions bonded to said integral unit fixing said integral unit in said casting and fixing said sleeves for access to said bores thereof from exteriorly of said casting. 